Hydrotherapy units which provide aerated heated water for physical therapy or for relaxation, hereafter sometimes referred to as a "spa", are known in the art and in recent years have been in increasing demand because of their recognized beneficial impact on users. In many cases, therapeutic devices of this kind are medically prescribed for persons with physical impairments who, because of such impairment, have difficulty in travelling to a therapy center away from home. Thus, the availability at moderate cost of a therapy unit as an accessory to a conventional private pool, would be a definite advantage. However, the expanded use of such units for private pool owners, whether for health purposes or for relaxation, has been slowed primarily because of the relatively high cost of such devices.
The existence of floating pools per se is known, see for example U.S. Pat. Nos. 3,078,472 and 3,099,018. Various therapeutic units, see for example, U.S. Pat. Nos. 3,092,101 and 3,693,194 are also known. Moreover, attempts have also been made in the prior art to provide therapeutic units as an adjunct to swimming pools and which use the heating systems of the main pool such as U.S. Pat. Nos. 3,623,165, 3,781,925, and 3,837,016. However, no specific unit is known which provides the private pool owner with an inexpensive, portable and yet effective therapy unit which may be readily used with, and removed from, an existing swimming pool and uses the existing facilities thereof, is light in weight, does not alter the integrity of an existing conventional pool, and is reliable and effective in performance. It is thus apparent that a need exists for a therapy unit or health spa which is of low cost and is readily adaptable to be used as an accessory to an existing conventional pool which may be removably installed and used without disturbing the integrity of the conventional pool.